Try laser/mortar jumping and bunnyhopping. Do you know how these work?
Also may I recommend to post your questions to the Xonotic forum (www.xonotic.org), since due to recent developments (viewtopic.php?f=4&t=6079) the nexuiz community has abandoned this forum. You'll most probably get more sophisticated help over there, maybe someone even has a demo on how to finish that map. I didn't play the single player campaign for ages...
Cheers!
<Community>: Why was the name "Nexuiz" licensed to IllFonic in a way that allows IllFonic to use the name without any suffix or subtitle for a commercial console game? <Lee Vermeulen>: <Community>: http://www.xonotic.org
<Community>: Why was the name "Nexuiz" licensed to IllFonic in a way that allows IllFonic to use the name without any suffix or subtitle for a commercial console game? <Lee Vermeulen>: <Community>: http://www.xonotic.org